JP2014209825A - Power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation system that allows improving utilization efficiency of power generation energy and reducing manufacturing cost.SOLUTION: A power generation system of the present invention includes: a cogeneration device 1 having a power generation device 11, a heat emission circuit 12, a DC converter 13, an AC converter 14, a heater 15 driven by surplus generation power, and control section 16; and a natural-energy generation device 2 having an output terminal connected to a connection point A between the DC converter 13 and the AC converter 14, and driven by natural energy. In converting an inputted DC input power into AC power and transmitting the AC power to an AC system, the AC converter 14 adjusts a current value so that the voltage of the input power is constant at a predetermined voltage and converts the input power into the AC power. The heater 15 is connected in parallel to the connection point A, and the natural-energy generation device 2 supplies DC power to the connection point A.

Description

  The present invention relates to a power generation system including one AC converter for a plurality of power generation devices.

  Japanese Unexamined Patent Application Publication No. 2003-250222 discloses a grid interconnection system including one AC converter for a plurality of distributed power generation sources. In this grid connection system, the DC input voltage of the AC converter is controlled to be constant at a predetermined voltage. Thereby, it is possible to perform system interconnection with a common AC converter for a plurality of distributed power generation sources.

  In a power generation system including a plurality of power generation devices (distributed power generation sources), the grid interconnection system does not need to be provided with a plurality of AC converters, and can reduce the number of parts and the cost.

JP 2003-250222 A

  By the way, recently, from the viewpoint of energy saving, a cogeneration apparatus that uses the exhaust heat of the power generation apparatus for heating or the like has attracted attention. In a power generation system including a cogeneration apparatus, further improvement in energy efficiency and cost reduction and downsizing for system diffusion are required.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a power generation system capable of improving the utilization efficiency of power generation energy and reducing the manufacturing cost.

A power generation system according to aspect 1 of the present invention includes (1) a power generation apparatus that generates power by supplying fuel, and a heat medium that is circulated and recovered to supply exhaust heat generated by the power generation apparatus to a heat load. An exhaust heat circuit, a DC converter for converting the output of the power generation device, an AC converter connected to the DC converter, a heater for driving the heating medium driven by surplus generated power, and A cogeneration device having a control unit that controls power generation of the power generation device, and (2) a natural power source that uses natural energy as a drive source, with an output terminal connected to a connection point between the DC converter and the AC converter. An energy generator,
The AC converter adjusts a current value so that a voltage of the input power is constant at a predetermined voltage when the input DC power is converted into AC power and transmitted to the AC system, and the input power is adjusted. Is converted into the AC power, the heater is connected in parallel to the AC converter with respect to the connection point, and the natural energy power generator supplies DC power to the connection point.

  The power generation system according to aspect 2 of the present invention is the above-described aspect 1, wherein the natural energy power generation device is a solar power generation device including a solar cell unit including one or a plurality of solar cells, and the predetermined voltage is The voltage value is set at the maximum power point of the solar cell unit.

  In the power generation system according to aspect 3 of the present invention, in the aspect 2, the solar cell unit includes a plurality of solar cells connected in series, and the predetermined voltage is a maximum power point of each of the solar cells connected in series. Is set to the total voltage value at.

  The power generation system according to aspect 4 of the present invention is the power generation system according to any one of aspects 1 to 3, wherein the natural energy power generation device includes a solar cell unit including one or a plurality of solar cells, and the solar cell unit. It is a photovoltaic power generation device comprising a connected storage battery and a charge / discharge control unit that controls charging / discharging of the storage battery, and the voltage value at the maximum power point of the solar battery unit is set to the charging voltage of the storage battery Has been.

  The electric power generation system which concerns on aspect 5 of this invention is equipped with the said some natural energy electric power generation apparatus connected to the said connection point in one of the said aspects 1-4.

A power generation system according to aspect 6 of the present invention is the power generation system according to any one of aspects 1 to 5,
It is attached to a building with a living room,
A heating device for heating the living room directly or indirectly by the heat medium;
A heat medium control device for controlling the flow of the heat medium in the heating device;
A building information management device that sets, acquires, and manages the building information, a control unit of the cogeneration device, the natural energy power generation device, and a main control device that controls the heat medium control device;
Have
The building information management device has a temperature sensor that measures a room temperature of the room and an operation device that can set a target temperature that is a target value of the temperature of the room by an operator,
The main control device performs a natural energy heating operation for controlling the heat medium control device so that the heat medium flows through the heating device when the target temperature managed by the building information management device is higher than the room temperature.

The power generation system according to aspect 7 of the present invention is the power generation system according to aspect 6, wherein the building information management device includes a required power amount acquisition unit that acquires power required by the building, and the natural energy power generation. It has natural energy power generation amount acquisition means to acquire the power generation amount of the device,
The main controller performs the natural energy heating operation when the required power amount managed by the building information management device is smaller than the natural energy generation amount.

A power generation system according to aspect 8 of the present invention is the power generation system according to aspect 6 or 7, and includes a hot water storage device that stores hot water heated by the heat medium directly or indirectly,
The heat medium control device controls the flow of the heat medium in the hot water storage device,
When the natural energy heating operation is not performed, the main control device performs a hot water storage operation for controlling the heat medium control device so as to store hot water as long as hot water is stored in the hot water storage device.

  According to the power generation system of the present invention, since the heater is connected in parallel with the AC converter with respect to the connection point, surplus has occurred in the total power generated by the power generation device of the cogeneration device and the natural energy power generation device. In this case, a direct current is supplied to the heater. That is, not only the power generator but also the surplus power of the natural energy power generator can be used for heating the heat medium of the exhaust heat circuit. ADVANTAGE OF THE INVENTION According to this invention, the generated energy of the natural energy power generating apparatus from which generated electric power fluctuates can be utilized without waste, and the utilization efficiency of generated energy can be improved. The heater can also be connected in parallel with the AC converter to the AC system after AC power conversion.

  Moreover, according to this invention, the expensive storage battery for charging the surplus electric power which the natural energy power generation apparatus generated is not necessarily required, and it becomes possible to reduce manufacturing cost. Further, since the AC converter and the heater can be shared by the cogeneration apparatus and the natural energy power generation apparatus, the number of parts and the manufacturing cost can be reduced.

  Furthermore, since the room can be heated using natural energy, the energy can be effectively used.

It is a block diagram which shows the structure of the electric power generation system of 1st embodiment. It is a circuit diagram which shows the circuit structure of the electric power generation system of 1st embodiment. It is a flowchart for demonstrating control of the electric power generation system of 1st embodiment. It is a flowchart for demonstrating control of the electric power generation system of 1st embodiment. It is a block diagram which shows the structure of the electric power generation system of 2nd embodiment. It is a block diagram which shows the structure of the electric power generation system of 3rd embodiment. It is a block diagram which shows the structure of the electric power generation system of a reference example. It is a block diagram which shows the structure of the electric power generation system of a deformation | transformation form. It is a flowchart for demonstrating control of the electric power generation system of a deformation | transformation form. It is a flowchart for demonstrating control of the electric power generation system of a deformation | transformation form. It is a figure which shows typically the fluctuation | variation by the time of the electric power generation amount and hot water supply amount when the electric power generation system of a deformation | transformation form is operating (intermediate periods, such as spring and autumn).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings. Each figure used for explanation is a conceptual diagram.

<First embodiment>
As shown in FIG. 1, the power generation system of the first embodiment includes a cogeneration device 1 and a solar power generation device (corresponding to a “natural energy power generation device”) 2. The cogeneration apparatus 1 includes a power generation device 11, an exhaust heat circuit 12, a DC converter 13, an AC converter 14, a heater 15, and a control unit 16.

  The power generation device 11 is a device that generates power by being supplied with fuel. Specifically, the power generation device 11 includes an engine 111 and a generator 112. The engine 111 is a gas engine that uses gas as fuel. The generator 112 is a device that generates power by driving the engine 111.

  The exhaust heat circuit 12 includes a pipe 121, a heat exchanger 122, a heat storage device 123, and a cordene engine cooling pump 124. The pipe 121 is a pipe (circulation circuit) through which cooling water of the engine 111 (corresponding to “heat medium”) flows. The cordene engine cooling pump 124 is an electric pump installed with respect to the pipe 121, and distributes cooling water in the pipe 121. The cooling water in the pipe 121 exchanges heat with the heat of the engine 111 generated when the engine 111 is driven to cool the engine 111. The cooling water cools the engine 111 and collects exhaust heat of the engine 111. The exhaust heat is, for example, heat generated by the engine 111 or heat of exhaust gas.

  The heat exchanger 122 is disposed in the heat storage device 123 and exchanges heat between the heat storage medium (for example, water) in the heat storage device 123 and the cooling water in the pipe 121. The heat storage device 123 is a hot water storage tank that houses a heat storage medium therein, and supplies the heat storage medium to a heating device (corresponding to a “heat load”) such as floor heating (not shown). Thus, the exhaust heat circuit 12 collects the exhaust heat and supplies it to the heat storage device 123 in order to supply the exhaust heat accompanying the power generation of the power generation device 11 to the heating device or the like through which the cooling water circulates.

  The DC converter 13 is a converter, and is a device that converts the generated power of the power generation device 11 into DC power. The DC converter 13 has an input terminal connected to the power generator 11 and converts the output voltage of the power generator 11. The DC converter 13 can employ a DC-DC converter when the generated power is DC power.

  The AC converter 14 is a device that converts a DC voltage into an AC voltage so that it can be connected to a commercial power source. Specifically, the AC converter 14 includes an inverter 141 and a voltage constant control unit 142. One of the inverters 141 is connected to the DC system 7 (connection point A), and the other is connected to the AC system 8 (commercial power supply Z). The connection point A is a point on the electric circuit 91 that connects the DC converter 13 and the AC converter 14. A solar power generation device 2 to be described later is connected to the connection point A. Details of the AC converter 14 will be described later.

  The heater 15 is an electric heater that is driven by a DC voltage, and is installed so that the cooling water can be heated with respect to the exhaust heat circuit 12. An input terminal of the heater 15 is connected to an electric circuit 91 between the connection point A and the inverter 141. The heater 15 and the inverter 141 are both connected to the connection point A. The heater 15 is connected to the connection point A in parallel with the AC converter 14. The heater 15 is driven by surplus power of DC power supplied from the connection point A, and heats the cooling water flowing through the exhaust heat circuit 12 toward the heat storage device 123.

  The control unit 16 is an electronic control unit (ECU) and controls driving of the power generation device 11. The control unit 16 is controllably connected to the power generation device 11, the electric pump, the DC converter 13, and the AC converter 14 and controls the cogeneration apparatus 1 as a whole. In the present embodiment, the control unit 16 controls the driving of the power generation device 11 according to the amount of use of an electric load (not shown) connected to the commercial power supply Z. The control unit 16 controls the output conversion amount in the inverter 141 together with the voltage constant control unit 142, and controls the DC input voltage to a predetermined voltage while observing the DC input voltage. The control unit 16 may control the power generation device 11 in consideration of the power generation amount of the solar power generation device 2.

  Here, the AC converter 14 will be further described. As shown in FIG. 2, a constant voltage control unit 142 is connected to the inverter 141. The constant voltage control unit 142 is an ECU that controls the current value so that the DC input voltage of the AC converter 14 is constant at a predetermined voltage. The constant voltage control unit 142 is also connected to the control unit 16.

  The constant voltage control will be described. In the description, reference can be made to the grid interconnection system described in Japanese Patent No. 3950706. The following control is executed by the constant voltage control unit 142 or the control unit 16. When the voltage of the DC power of the DC system (DC input voltage of the AC converter 14) V1 is “D”, the input current from the DC side of the AC converter 14 is “0”. As shown in FIG. 3, first, control of the current control converter 13a provided in the DC converter 13 is started (S11). And it is discriminate | determined whether the output electric power of the electric power generating apparatus 11 is "0" (S12). When it is determined that the output power is “0” (S12: Yes), the voltage V1 is smaller than “D”, and the process returns to S12.

  On the other hand, when it is determined that the output power is not “0” (S12: No), the current control converter 13a is controlled to make the voltage V1 larger than “D” (S13). Thereby, the DC current of the DC converter 13 flows out to the connection point A (S14), and the voltage V1 rises (S15). The current is superimposed at connection point A. Then, inverter control is executed in the AC converter 14 (S16). Then, it is determined whether or not the output voltage V2 of the DC converter 13 is “D” (S17). When it is determined that the voltage V2 is “D” (S17: Yes), the current control converter 13a clamps (fixes) the voltage V2 in order to protect the power generation device 11 and the DC converter 13 from an abnormal situation. (S18).

  On the other hand, when it is determined that the voltage V2 is not an overvoltage (S17: No), it is determined whether or not the output voltage V3 of the power generator 11 is greater than the optimum value (S19). When it is determined that the voltage V3 is larger than the optimum value (S19: Yes), the current control converter 13a is controlled to increase the voltage V3 to the optimum value, and the direct current of the DC converter 13 is increased (S20). When it is determined that the voltage V3 is less than or equal to the optimum value (S19: No), it is determined whether or not the voltage V3 is less than the optimum value (S21). When it is determined that the voltage V3 is less than the optimum value (S21: Yes), the current control converter 13a is controlled to reduce the DC current of the DC converter 13 (S22). When it is determined that the voltage V3 is not less than the optimum value (S21: No), the current control converter 13a is controlled to maintain the output voltage V3 of the power generator 11 at the optimum value, and the current value of the DC converter 13 is maintained. (S23).

  In the inverter control (S16), as shown in FIG. 4, first, the control unit 16 sets “D” in the constant voltage control unit 142 (S31). “D” has the above meaning and is also a reference value that does not regenerate DC power of the DC system for the AC system connected to the commercial power supply Z. Then, the AC converter 14 is connected to the commercial power supply Z via the safety device on the condition that the voltage V1 becomes larger than the minimum operating voltage of the AC converter 14 (inverter) (S32).

  Here, when the voltage V1 is smaller than “D”, an alternating current flows from the commercial power supply Z to the alternating current converter 14, and the voltage V1 increases (S33). As a result, the voltage V1 approaches “D”. When the voltage V1 is greater than “D”, the DC current of the DC system 7 (current flowing through the connection point A) flows to the AC system 8 (commercial power supply Z side) via the AC converter 14 (S34). As a result, the voltage V1 decreases and the voltage V1 approaches “D”. When the output power of the power generation device 11 and the solar power generation device 2 is close to “0”, the voltage V1 is kept at “D”, but the flow into the DC system 7 or the AC system 8 via the AC converter 14 The output is offset and the current value of the DC power of the DC system 7 is “0”. As shown in FIG. 3, when the control of the current control converter 13a is started, a direct current flows through the connection point A.

  Thereafter, the constant voltage control unit 142 determines whether or not the voltage V1 is greater than “D” (S37). When it is determined that the voltage V1 is greater than “D” (S37: Yes), the constant voltage control unit 142 performs control to increase the current value of the AC power converted from the DC power with respect to the AC converter 14. (S38). On the other hand, when the voltage V1 is determined to be equal to or lower than “D” (S37: No), the voltage constant control unit 142 determines whether the voltage V1 is less than “D” (S39).

  When it is determined that the voltage V1 is less than “D” (S39: Yes), the constant voltage control unit 142 controls the inverter 141 to reduce the current value of the AC power converted from the DC power (S40). . On the other hand, when it is determined that the voltage V1 is not less than “D” (S37: No), the constant voltage control unit 142 controls the inverter 141 to maintain the current value of the AC power converted from the DC power. (S41). As described above, the AC converter 14 of the present embodiment converts the DC power of the DC system into AC power and transmits the AC power to the AC system. The current value is determined based on the voltage value V1 of the DC power of the DC system. The DC power is converted into AC power so that the voltage value of the DC power is constant at a predetermined voltage. Thereby, one AC converter 14 is sufficient for a plurality of power generation devices.

  The solar power generation device 2 includes a solar cell unit 20 including a plurality of solar cells 21 and a DC converter 22. Each solar cell 21 is a so-called solar cell module formed in a panel shape. The solar cell unit 20 is configured by connecting a plurality of solar cells 21 in series and in parallel.

  The DC converter 22 has the same configuration as the DC converter 13, and has an input terminal connected to the output terminal of the solar cell unit 20 and an output terminal connected to the connection point A. The DC converter 22 has a current control converter (not shown) and exhibits the same function as the DC converter 13. At the connection point A, a direct current of the generated power from the power generation device 11 and the solar power generation device 2 is superimposed and flows, and a direct current system using the generated power is formed.

  According to the power generation system of the first embodiment, since the heater 15 is connected in parallel with the AC converter 14 with respect to the connection point A, the surplus is the sum of the power generated by the power generation device 11 and the solar power generation device 2. When this occurs, a direct current is supplied to the heater 15. That is, according to the first embodiment, not only the power generator 11 but also the surplus power of the solar power generator 2 is used to heat the cooling water of the exhaust heat circuit 12. That is, the heater 15 is shared by the cogeneration apparatus 1 and the solar power generation apparatus 2. As described above, in the power generation system according to the first embodiment, in the plurality of power generation apparatuses 11 and 2, the AC converter 14 is shared for the electrical load, and the heater 15 is shared for the thermal load. Thereby, it is possible to use the generated power of the solar power generation apparatus that is environmentally friendly but the generated power fluctuates without waste, and energy efficiency can be improved.

  Moreover, according to 1st embodiment, since the electric power generated by the solar power generation device 2 can be used without waste without using an expensive storage battery, the manufacturing cost can be reduced. In addition, since the AC converter 14 and the heater 15 can be shared for a plurality of power generators, the number of parts and the manufacturing cost can be reduced. In addition, the shared configuration can save space. Further, even when the cogeneration apparatus 1 is in an emergency state (for example, a failure or a situation in which fuel is not supplied), the heater 14 is driven by the generated power of the solar power generation apparatus 2 that does not require fuel and the power to the commercial power supply Z. Supply becomes possible.

  When a power generation device using natural energy such as sunlight or wind power is used as one of a plurality of power generation devices, the problem is that the generated power fluctuates depending on the surrounding conditions. For example, since the surplus power generated can be used as heat, the utilization efficiency of the generated power can be improved.

<Second embodiment>
As shown in FIG. 5, the power generation system of the second embodiment has no DC converter 22 and a plurality of solar cells 21 in the solar cell unit 20 are connected in series under predetermined conditions as compared to the first embodiment. Is different. That is, the solar power generation device 2 of the second embodiment does not have the DC converter 22 but includes the solar cell unit 20. About the structure similar to 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The voltage value (maximum output operating voltage) at the maximum power point of the solar cell unit 20 is the sum of the voltage values at the maximum power points of the solar cells 21 connected in series. Here, the plurality of solar cells 21 constituting the solar cell unit 20 of the second embodiment is configured such that the maximum output operating voltage of the solar cell unit 20 (the entire solar cell 21) is the voltage V1 that the voltage constant control unit 142 keeps constant. Are connected in series so that That is, the maximum output operating voltage of the solar cell unit 20 is equivalent to the DC input voltage V1 of the AC converter 14. In other words, the DC input voltage V <b> 1 (predetermined voltage) of the AC converter 14 is set to a voltage value at the maximum output point of the solar cell unit 20.

  The output terminal of the solar cell unit 20 of the second embodiment is directly connected to the connection point A. For example, when the maximum output operating voltage of the solar cell 21 is 50V and the input voltage V1 of the AC converter 14 is set to 350V, the solar cell unit 20 is configured by seven solar cells 21 connected in series. Is done. The solar cell unit 20 may have a configuration in which seven solar cells 21 are set as one set and a plurality of sets are connected in parallel. That is, the power generation system of the second embodiment may have a configuration excluding the DC converter 22 in the configuration of FIG. 1 (the configuration of the first embodiment).

  According to the power generation system of the second embodiment, the same effect as the first embodiment is exhibited. Furthermore, according to the second embodiment, the maximum output operating voltage of the solar cell unit 20 is set to be equal to the DC input voltage V1 of the AC converter 14, for example, by connecting a plurality of solar cells 21 in series as described above. Therefore, there is no need to arrange a DC converter such as a booster circuit between the solar cell unit 20 and the AC converter 14. Further, since the AC converter 14 controls the input voltage V1 to be constant at the maximum output operating voltage of the photovoltaic power generator 2, the photovoltaic power generator 2 does not have an MPPT (maximum power point tracking) control circuit. It can generate electricity with maximum efficiency. According to the second embodiment, the system can be simplified, reduced in cost, and reduced in size.

  In addition, in consideration of obtaining a high voltage (for example, AC 200 V) necessary for the AC system 8, a plurality of solar cells 21 can be used rather than achieving the above configuration (a configuration in which the maximum output operating voltage and the voltage V1 are matched). It is more advantageous in terms of cost to connect the solar cells 21 in series to achieve the above configuration because a general-purpose solar cell 21 can be used.

<Third embodiment>
As shown in FIG. 6, the power generation system of the third embodiment further includes a storage battery 3 and a charge / discharge control unit 4, and a plurality of solar cells 21 constituting the solar cell unit 20, as compared with the first embodiment. The difference is that they are connected in parallel under predetermined conditions. About the structure similar to 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The storage battery 3 is a rechargeable secondary battery, such as a lead storage battery or a lithium ion battery. The storage battery 3 is connected to the output terminal of the solar cell unit 20 and the input terminal of the DC converter 22 via the charge / discharge control unit 4. The charging / discharging control unit 4 is a general charging / discharging circuit, supplies charging power from the generated power of the solar cell unit 20 to the storage battery 3, and the generated power of the solar cell unit 20 is insufficient for the request. In some cases, power is supplied to the DC converter 22.

  The plurality of solar cells 21 constituting the solar cell unit 20 are connected so that the maximum output operating voltage of the solar cell unit 20 is equivalent to the charging voltage of the storage battery 3. In other words, the voltage value at the maximum output point of the solar cell unit 20 matches the charging voltage of the storage battery 3. For example, when the charging voltage of the storage battery 3 is 15V and the maximum output operating voltage of the solar battery 21 is 15V, all the solar batteries 21 of the solar battery unit 20 are connected in parallel. Further, for example, when the charging voltage of the storage battery 3 is 30V and the maximum output operating voltage of the solar battery 21 is 15V, two solar batteries 21 connected in series are set as one set, and a plurality of sets are connected in parallel to form a solar battery. The unit 20 is manufactured.

  According to the power generation system of the third embodiment, the same effect as that of the first embodiment is exhibited. Moreover, according to 3rd embodiment, a separate converter is not required but the electric power generated by the solar power generation device 2 can be directly supplied to the storage battery and charged. By connecting the solar cells 21 in parallel, the output (generated power) of the solar cell unit 20 can be maintained. As described above, according to the third embodiment, the system can be simplified, reduced in cost, and reduced in size.

<Deformation>
-Configuration In the first embodiment to the third embodiment described above, the following configuration can be adopted. The power generation system of this modification is disposed in a building having a living room. In the following, description will be given with emphasis on parts having different configurations.

  As shown in FIG. 8, the power generation system of this variation mode includes a heat exchanger 122A provided in the heat storage device 123, a heating water circulation pump 124A, a heating device 19 (floor heating, panel heater, etc.), and a closed connection between them. The point which has the heating circuit 12A of the heat medium which consists of piping 121A which is a circuit, it replaces with the control apparatus 16, and control which also controls the heating circuit 12A including the building information management apparatus which sets, acquires, and manages the information in a building The device 16A has a temperature sensor 161 that measures the temperature of the room and sends it as a temperature signal to the control device 16A, and an operation panel 162 (corresponding to the operation device) that can operate the building information management device. Different from the power generation system of one embodiment.

  Although FIG. 8 is described based on the system of the first embodiment (FIG. 1), the same is based on the power generation system of the second embodiment (FIG. 5) and the power generation system of the third embodiment (FIG. 6). The following explanation is valid for those that have been changed (parts with the same reference numerals as those changed from FIG. 1 to FIG. 8 can be similarly changed). Hereinafter, the control method of the electric power generation system in the modification from 1st embodiment is demonstrated.

-Control method Characteristic operation | movement of the electric power generation system of this modification is demonstrated based on FIGS. FIG. 11 is a graph schematically showing the power generation amount, the power sales amount, the cogeneration power generation amount, and the hot water supply amount when the power generation system of this modification is operated in the intermediate period (spring, autumn).

  When this system is activated, it is determined whether or not the current season is summer (S50). This is because the room is not heated in summer. Note that this step is omitted when used in an environment where heating is required even in summer. Whether it is summer or not is judged by date. The date is determined by a clock provided in the control device 16A.

(1-1: When it is not summer: S51-68: FIG. 9)
If it is not summer (“N” in S50), it is determined whether or not the natural energy heating operation mode is set (S51). Set to the natural energy heating operation mode except in special cases. Here, as a special case, it is possible to exemplify a case where it is clear that there is no person in the room, such as when the user is away from home for a long period of time, or a case where the operator himself selects not to perform heating using the operation panel 162 . Whether or not there is a person in the living room can be determined by the control device 16A. Since the building information management device is incorporated in the control device 16A, it is possible to determine whether or not a person is living in the building from events such as power, water supply, opening and closing of keys and doors. In addition, in this form, as natural energy uses sunlight, it can be determined that it is not in the natural energy heating operation mode even when the sun from the evening to the morning sinks and solar power generation is not enough, time etc. It is possible to automatically switch whether or not it is a natural energy heating operation mode based on the above.

(2-1: When the natural energy heating operation mode is set: S52 to S60)
When the natural energy heating operation mode is set (“Y” in S51), the cogeneration is stopped (S52). Then, it is determined whether or not the room temperature calculated based on the temperature signal from the temperature sensor 161 is lower than the set temperature (S53). The set temperature is a temperature set by the operator using the operation panel 162 or a temperature automatically set by the control device 16A. The control device 16 </ b> A can adopt, as the set temperature, a temperature that is considered comfortable from the history of operation of the operator so far, the outside air temperature, the season, and the like.

  If the room temperature is lower than the set temperature, aim to heat. First, it is determined whether the amount of photovoltaic power generation exceeds the base power. If it exceeds, surplus power is present, the power is used for heating the room (S55 to S58). Here, the base power is power consumed by a building calculated from building information managed by the control device 16A.

  If it does not exceed, avoid using the electric power obtained by solar power generation directly for heating (S59, S60).

  When the amount of photovoltaic power generation exceeds the base power, the cogeneration engine cooling pump 124 and the heating water circulation pump 124A are operated (S55). At that time, the electric power obtained by the photovoltaic power generation is energized to the heater 15 (S56). Then, the heat generated from the heater 15 warms the cogeneration cooling water and heats the heat storage medium in the heat storage device 123. The heat medium in the heating circuit 12A is heated via the heated heat storage medium, and the heat is transmitted to the heating device 19 to heat the room (S57, S58). The degree of energization of the heater 15 is an amount obtained by excluding the base power from the power obtained by solar power generation. Electric power corresponding to the base electric power is supplied to the AC system 8 through the inverter 141 and consumed.

  If the amount of photovoltaic power generation does not exceed the base power, the cogeneration engine cooling pump 124 and the heating water circulation pump 124A are not operated (S59). The heater 15 is not energized (S60). As a result, no heat is supplied to the heating device 19 and the room is not heated by the heating device 19.

(2-2: When the natural energy heating operation mode is not set: S61 to S68)
When the natural energy heating operation mode is not set ("N" in S51), the natural energy hot water storage mode is set (S61). Of the electric power obtained from natural energy, the portion exceeding the base electric power is effectively used by storing it as hot water.

  First, it is determined whether the amount of photovoltaic power generation exceeds the base power (S62). When it exceeds, surplus electric power exists, so that electric power is stored as hot water (S63 to S66). If not, the power obtained by solar power generation is used as part of the base power (S67, S68).

  When the amount of photovoltaic power generation exceeds the base power, the cogeneration engine cooling pump 124 is operated and the heating water circulation pump 124A is operated (S63). At that time, the electric power obtained by the photovoltaic power generation is energized to the heater 15 (S64). Then, the heat generated from the heater 15 warms the cogeneration cooling water (S65), and heats the heat storage medium in the heat storage device 123. The heat generated by the heater 15 heats the heat storage medium (water) and stores it as hot water (S66). The degree of energization of the heater 15 is an amount obtained by excluding the base power from the power obtained by solar power generation. Electric power corresponding to the base electric power is supplied to the AC system 8 through the inverter 141 and consumed.

  When the amount of photovoltaic power generation does not exceed the base power, the cogeneration engine cooling pump 124 and the heating water circulation pump 124A are not operated (S67). The heater 15 is not energized (S68). As a result, the cogeneration cooling water is not heated. The electric power obtained by solar power generation is used as part of the base electric power.

(1-2: In case of summer: S69 to 78: FIG. 10)
When it is summer (“Y” in S50), heating is not required, so the natural energy hot water storage mode is set (S69). Of the electric power obtained from natural energy, the portion exceeding the base electric power is effectively used by storing it as hot water.

  First, it is determined whether or not the temperature of the cogeneration cooling water exceeds an appropriate temperature (for example, 85 ° C.) (S70). This is because it is not desirable to heat to an appropriate temperature or higher. Here, the fact that the temperature of the cogeneration cooling water is equal to or higher than the appropriate temperature is estimated that the temperature of the heat storage medium exchanging heat with the cogeneration cooling water is also equal to or higher than the appropriate temperature.

  When the temperature of the cogeneration cooling water is higher than the appropriate temperature (“Y” in S70), since no more hot water storage is desirable, the solar power generation device 2 is controlled so as to generate power for the base power, or The photovoltaic power generation is stopped (S76).

  When the temperature of the cogeneration cooling water does not exceed the appropriate temperature (“N” in S70), surplus power can be effectively used by hot water storage. In that case, it is first determined whether or not the amount of photovoltaic power generation exceeds the base power (S71). If it exceeds, there is surplus power, so that power is stored as hot water (S72 to S75). If not, the electric power obtained by solar power generation is used as part of the base electric power (S77, S78).

  When the amount of photovoltaic power generation exceeds the base power, the cogeneration engine cooling pump 124 is operated and the heating water circulation pump 124A is operated (S72). At that time, the electric power obtained by the photovoltaic power generation is energized to the heater 15 (S73). Then, the heat generated from the heater 15 warms the cogeneration cooling water (S74), and heats the heat storage medium in the heat storage device 123. The heat generated by the heater 15 heats the heat storage medium (water) and stores it as hot water (S75). The degree of energization of the heater 15 is an amount obtained by excluding the base power from the power obtained by solar power generation. Electric power corresponding to the base electric power is supplied to the AC system 8 through the inverter 141 and consumed.

  If the amount of photovoltaic power generation does not exceed the base power, the cogeneration engine cooling pump 124 and the heating water circulation pump 124A are not operated (S77). The heater 15 is not energized (S78). As a result, the cogeneration cooling water is not heated. The electric power obtained by solar power generation is used as part of the base electric power.

  As described above, according to the power generation system of the present modification, the same effects as those of the first embodiment to the third embodiment are exhibited, and effective use of power obtained by solar power generation is achieved. Can do. For example, effective use of electric power can be realized by using surplus electric power among electric power obtained by solar power generation for heating or hot water storage. In particular, since power generation is possible as long as sunlight falls, heating and hot water storage can be performed under conditions where surplus power exists. Since hot water can be stored effectively, there is no need to prepare a large water heater, and a small water heater can be used. Moreover, there is a possibility that the hot water container itself can be made unnecessary. Moreover, since the apparatus which converts the electric power obtained by photovoltaic power generation from the first embodiment to the third embodiment can also be used as a cogeneration apparatus, these functions can be realized simply by adding only the solar battery 21. become. Moreover, the solar cell itself can be of a small size that can be used for hot water supply and heating.

<Others>
The present invention is not limited to the above embodiment. For example, a wind power generator may be installed instead of the solar power generator 2. In this case, a DC converter that converts the generated power of the wind power generator into DC power is disposed between the connection point A and the generator of the wind power generator. Moreover, the cogeneration apparatus 1 should just be an electric power generation system which collect | recovers exhaust heat, and uses it for a heat load, for example, as the electric power generation apparatus 11, the fuel cell which uses hydrogen and air as a fuel may be used. Further, the fuel of the engine 11 is not limited to gas fuel such as natural gas or propane gas, but may be liquid fuel such as gasoline, kerosene, or light oil.

  Moreover, the control part 16 may control the electric power generating apparatus 11 according to the use condition of a thermal load instead of an electrical load or in addition to an electrical load. A plurality of power generation devices may be connected to one cogeneration device 1. For example, a plurality of solar power generation devices 2 may be connected to the connection point A, or a wind power generation device or a fuel cell system may be connected to the connection point A in addition to the solar power generation device 2. Also by these structures, the same effect as the said embodiment is exhibited.

<Reference example>
Further, as shown in FIG. 7, a system in which the heater 15 is not shared by a plurality of power generation devices can be cited as a reference example. It demonstrates with the code | symbol of the said embodiment. The power generation system 100 includes a plurality of power generation apparatuses 11 and 20. The power generators 11 and 20 are connected at a connection point A, and power is supplied from the DC system 7 to the AC system 8 by one AC converter 14. Even in this case, as described above, the AC exchanger 14 is controlled so as to keep the DC input voltage constant at a predetermined voltage. The solar cell unit 20 is configured such that a plurality of solar cells 21 are connected in series, and the maximum output operating voltage matches the predetermined voltage. Thereby, it is not necessary to provide a DC converter or an MPPT circuit for the solar power generation device 2.

  Similarly, in the power generation system 100 that does not share the heater 15 as in the third embodiment, the solar cells 21 are connected in parallel, and the maximum output operating voltage of the solar cell unit 20 and the charging voltage of the storage battery are matched. The storage battery can be directly charged with the generated power. Thus, the power generation system 100 has a configuration in which the DC converter 22 and the heater 15 are excluded from the configuration in FIG. 1, a configuration in which the heater 15 is omitted in the configuration in FIG. 5, or a configuration in which the heater 15 is omitted in the configuration in FIG. It may be. With these configurations, the system can be simplified, reduced in cost, and reduced in size.

DESCRIPTION OF SYMBOLS 1: Cogeneration apparatus, 11: Power generation apparatus, 111: Engine, 112: Generator, 12: Waste heat circuit, 13: DC converter, 14: AC converter, 141: Inverter, 142: Voltage constant control part, 15 : Heater, 16: control unit, 2: solar power generation device (natural energy power generation device), 20: solar cell unit, 21: solar cell, 22: DC converter, 3: storage battery, 4: charge / discharge control unit, Z :Commercial power supply

Claims (8)

A power generation device that generates power by being supplied with fuel, an exhaust heat circuit that collects heat to circulate through the heat medium and supply exhaust heat associated with power generation to the heat load, and converts the output of the power generation device to power A DC converter, an AC converter connected to the DC converter, a heater that is driven by surplus generated power to heat the heat medium, and a controller that controls power generation of the power generator. Generation equipment,
An output terminal is connected to a connection point between the DC converter and the AC converter, and a natural energy power generation apparatus using natural energy as a drive source;
With
The AC converter adjusts a current value so that the voltage of the input power becomes constant at a predetermined voltage when the input DC power is converted into AC power and transmitted to the AC system, and the input power is adjusted. Is converted into the AC power,
The heater is connected in parallel with the AC converter with respect to the connection point;
The natural energy power generation apparatus is a power generation system that supplies DC power to the connection point. In claim 1,
The natural energy power generation device is a solar power generation device including a solar cell unit composed of one or a plurality of solar cells,
The power generation system in which the predetermined voltage is set to a voltage value at a maximum power point of the solar cell unit. In claim 2,
The solar cell unit includes a plurality of solar cells connected in series,
The power generation system in which the predetermined voltage is set to the sum of voltage values at the maximum power points of the solar cells connected in series. In one of Claims 1-3,
The natural energy power generation apparatus includes a solar cell unit including one or a plurality of solar cells, a storage battery connected to the solar cell unit, and a charge / discharge control unit that controls charge / discharge of the storage battery. A photovoltaic device,
The power generation system in which the voltage value at the maximum power point of the solar cell unit is set to the charging voltage of the storage battery. In one of claims 1-4,
A power generation system comprising a plurality of the natural energy power generation devices connected to the connection point. The power generation system according to any one of claims 1 to 5,
It is attached to a building with a living room,
A heating device for heating the living room directly or indirectly by the heat medium;
A heat medium control device for controlling the flow of the heat medium in the heating device;
A building information management device that sets, acquires, and manages the building information, a control unit of the cogeneration device, the natural energy power generation device, and a main control device that controls the heat medium control device;
Have
The building information management device has a temperature sensor that measures a room temperature of the room and an operation device that can set a target temperature that is a target value of the temperature of the room by an operator,
The main control device performs a natural energy heating operation for controlling the heat medium control device to flow the heat medium to the heating device when the target temperature managed by the building information management device is higher than the room temperature.
Power generation system. The building information management device has necessary power amount acquisition means for acquiring power required by the building, and natural energy power generation amount acquisition means for acquiring the power generation amount of the natural energy power generation device,
The main control device performs the natural energy heating operation when the required power amount managed by the building information management device is smaller than the natural energy power generation amount,
The power generation system according to claim 6. A hot water storage device for storing hot water heated directly or indirectly by the heat medium;
The heat medium control device controls the flow of the heat medium in the hot water storage device,
The main control device performs a hot water storage operation for controlling the heat medium control device so as to store hot water as long as hot water is stored in the hot water storage device when the natural energy heating operation is not performed.
The power generation system according to claim 6 or 7.

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